Tri- and pentanuclear tungsten-(mu-S)-M clusters (M = W, Cu, Ag)

The thiotungstate Et4N]2OW(WS4)2], Et4N]2.1, containing the linear S2W(VI)(mu-S)2]2W(IV)=O] core, was prepared from Et4N]2WS4] in the presence of the sulfide scavenger Cd2+. Addition of 1,2-bis(o-diphenylphosphinophenyl)ethane (diphosphine) and Cu+ or Ag+ to solutions of 1 in MeCN/DMF led to coordination of the (diphosphine)Cu/Ag fragments to the terminal sulfido ligands of 1, yielding novel linear pentanuclear, heterometallic clusters mu-OW(IV)(DMF)(W(VI)S4)2]M(diphosphine)]2], 2 (M = Cu) and 3 (M = Ag). Along with 2, the trinuclear cluster mu-(W(VI)S4)Cu(diphosphine)(2)]], 4, was also obtained. The molecular and crystal structures of Et4N]2.1, 2.MeCN, 3.MeCN, and 4.2MeCN.CH2Cl2 have been determined.